Power and speed transmission for motor vehicles



June 27, 1944. R. LANG ETAL POWER AND SPEED TRANSMISSION FOR MOTOR VEHICLES Filed April 5, 1940 2 Sheets-Sheet 1 ANB June 27, 1944. R, LANG TAL 2,352,212

POWER AND SPEED TRANSMISSION FOR MOTOR VEHICLES Filed April 5, 1940 2 Sheets-Sheet 2 y v 224 y 223 i225 226 gr 22a ['W 272ml dll Jn vena/:g:

RICHARD LANG and FRITZ KOCH POWER AND SPEED TRANSMISSION FOR MOTOR VEHICLES Richard Lang, Ravensburg, and Fritz Koch, Friedrichshafen, Bodensee, Germany; vested in the Alien Property Custodian Application April 5, 1940, Serial No. 328,132 In Germany March 13, 1939 (Cl. 'I4-336.5)

l Claims.

Our invention relates to power and speed transmissions for motor vehicles and has special reference to transmissions of this kind which include a change speed gear with an automatically operated device for causing speed changes.

The main object of our invention is to provide a device which ls of special advantage with transmissions having a plurality of different speeds as for instance in connection with motor vehicles running on rails. Our device is comparatively simple in construction and yet it affords not much space and can easily be controlled.

According to our invention we provide an automaticaliy operated device for causing speed changes and manually operated means for iniluencing such automatic device. The automatic device includes a main operating member, for instance a multiple valve or the like adapted to control fiuid pressure conduits leading to the clutches to be operated in the change speed gear, and preferably also to the main clutch situated between the motor and the change speed gear. Consequently, by means of this single main member all the operations necessary for the speed changes are controlled. For the purpose of causing automatic operation in dependence on the vehicle speed, we provide a centrifugal governor rotated in dependence on this speed which acts on the main control or operating member causing this to operate also in dependence on the said speed. When speaking of fluid pressure we understand pressure exerted by means of a gas as well as by means of a liquid.

The action of such governor may again be influenced manually for example by means of a springloaded valve counteracting to the effect of the governor, the tension of the spring being varied by means of a hand or foot lever, which again at the same time may .be in direct or indirect operative connection with a control means for the fuel admission to the motor. For such fuel admission a carburetor may be provided or a fuel pump, as with Diesel engines.

When causing speed changes in the change speed gear elements therein have to be shifted, for example clutch members. Such shifting has to be perfected in certain relation to the position of other elements, for instance of the main clutch members and vice versa. That is why we provide means for influencing the afore-mentioned main operating member in dependence on the position of certain elements in the change speed gear or on the position of the main clutch members.

All this will be understood best when having reference to the drawings which represent an example embodying our invention.

Fig. l is a diagrammatical vertical section through a transmission arrangement.

Fig. 2 is a plan viewvon the governor.

Fig. 3 shows the circumference of the main operating member wound off in one plane, but on a larger scale.

Fig. 4 is a vertical section through another modification of such main operating member, also on an enlarged scale.

In Fig. 1 there is shaft I driving a centrifugal governor, the support 2 of which is provided with 8 single weights as shown in Fig. 2.

The pendulums are marked I |-I8. They have extensions or brackets 2I-28 of different height which prevent the Weights from further out ward movement, when they have come to bear against the surface 2|] of the support 2. The weights II, I2, I3, I4 have the smallest stroke, the weights I5, I6 about the double, and the weights I'I and I8 the triple stroke of the weights II to I4.

3| is a disc connected to the end of a. rod 32/35 which is guided in a bearing 33 and shaped into a toothed bar at |68. The upper end of rod 32/35 is journaled in a piston 60 sldable in a cylinder 6I. There is a connecting conduit 62 opening into casing 63 In which a control slide valve 64 is situated, loaded by a spring 65 which, at its other end, bears against disc 61 connected to rod 66. The slide valve 64 is provided with control ports 68. Casing 63 has outlet ports 69 as well as an annular channel 'I0 into which opens a conduit 12 extending from an oil pump II driven by the engine IIJI. The upper end of rod 66 is provided with a disc 'I3 bearing against the finger end 'I4 of double lever 14/ 15 journaled at 16. Said lever is connected to another lever 18 by means of rod TI. Lever 'I8 serves for regulating the fuel pump or carburetor 19. There are different positions of lever 15 marked a, b, c and d.

The driving engine of the motor vehicle is partly shown at IIII. Friction clutch |02 connects to the change speed gear mounted in casing |03. There are three pairs of gears in this gear box, namely IIN/|05, IUS/|01 and Hi8/|09. The various speeds are changed by means of two double acting clutches III/II2, |I3/II4 and II5/II6, II'I/IIB. Clutch halves III, II3, II5 and III are slidably splined to their respective shaft portions |2|, |23, |25 and |21. Clutch halves III and II3 and clutch halves IIS and III are engaged and disengaged alternately by means of double levers |22 and |24, respectively. Levers |22 and |24 are provided with extensions |26 and |28, respectively, to the ends of which piston rods |29 and |30 are connected with pistons |3| and |32, respectively. These pistons are adapted to slide in cylinders |33 and |34 to which pressure oil conduits |35, |36, |31, |30 are connected.

Furthermore, levers |26 and |26 are provided with slits |39 and |40, respectively, wherein pins |4| and |42 are adapted to slide. These pins are formed on the ends of rods |43 and |44, respectively, to the other ends of which control members |45 and |46, respectively, are connected. The latter each have an annular groove |41 and |48, respectively, forming a kind of valve sliding in surrounding cylinders to which pressure oil conduits |49, |50, and |52 are connected. The respective outlet ports are designated at |53 and |54.

Friction clutch |02 is also brought into engagement by pressure oil conducted thereto by means of conduit |55.

|60 is a control slide valve adapted to be rotated and to be displaced longitudinally inside of casing |6|. Connected to casing |6| are conduits |35, |36, |31, |38, |55 as well as the main feeding conduit |62 coming from the oil pump 1|. Another branch |96 of conduit |62 connects to conduits |49 and |50, leading to control members |45 and |46, respectively. Slide valve |60 has an annular groove |63 and also two longitudinal bores |64 and |65, the rst one opening at the left hand end, the other at the right hand end of member |60. At the left hand to explain the control travels the circumference of the slide valve is unrolled in Fig. 3 and shown on a somewhat enlarged scale.

As will be seen from this figure the circumference of the slide valve |60 is provided with four longitudinal rows of channels. Row I comprises channels 20|, 203, 205, 201 as well as 25| and 252. This row is adapted to be used for setting the first speed. Row II comprises channels 2| 2|2, 2|3, 2|4, 2|5, 2|1 and 26|, 262, 263. This row is adapted to be used for setting the second speed. Row III comprises channels 22|, 223, 225, 226l 221, 228 and 21|, 212, 213. This row is adapted to be used for setting the third speed. And row IV comprises channels 23|, 233, 235, 231 and 282, 293. This row is adapted to be used for setting the fourth speed of the change speed gear. The sign in the various channels indicates connection to the pressure oil feeding bore |64, Whereas the sign indicates connection to the outlet bore |65 through which the oil pressure is reduced.

The following table shows for each individual speed which dog clutches are engaged in the change speed gear and which conduits have to be connected to the feeding pressure oil conduit and to the outlet. Furthermore, the channels are indicated which have to be connected with the feeding bore |64 or with the outlet bore |65 for the purpose of causing engagement or disengagement of the friction clutch |02. The neutral position indicated in the fourth vertical column of the table is infrequently used, because as soon as one change clutch is disengaged, the other one is end of slide valve |60 there is an extension |66 35 immediately engaged.

Neutral 1 I1 position 111 Iv 104 105 106 107 104 105 www "iai 111 lait "s1-.s 1111112 }i;.

1 Ge" clutch engaged {111:115 1171118 115,110 1151116 115,116 Conduite to the cglinders 0| the gear clutches Connected with t needing oileondult 1:15, 13s 136,138 136,131 135,131 130,131 Connected with outlet 13s, 137 1:15, 137 135, 1:18 136,138 135,138 Ports connected with conduit 155 leading to the main friction clutch 252(+) 26l(+) 272() 273(+) 282(+) to the end of which a pinion |61 is connected meshing with toothed bar |66. Between the left end of casing |6| and the left hand end face |10 of member |60 a pressure spring |69 is provided tending to push member |60 to the right.

To the right hand end of casing |6| a cylinder |1| is mounted in which a second cylinder adapted to be displaced longitudinally is located. The latter has an annular groove |13 and also a stop |14. In cylinder |12 a piston |15 is sliding which is connected to a rod |16, having an end button |11 which bears against the slide valve |60. There is an outlet port |18. |19 and |60 are annular faces in the cylinders |1| and |12, respectively. Port |62 connects from space |13 to the inside of cylinder |12. To cylinder |1| are connected the two conduits |5| and |52.

The driven shaft |90 leaves the change speed gear at its left hand end. On this shaft which drives the vehicle a bevelled gear |9l is fixed which engages with a bevelled gear |92 fixed to shaft |93 by means of which shaft is rotated over pinions |94, |95.

Between the longitudinal bores |64 and |65 in the slide valve |60 and its circumference suitable connecting channels extending radially or substantially radially are provided which are not shown in Fig. 1, for simplicitys sake. In order The operation of the control device represented in Figs. 1 to 3 is as follows:

Shaft of the centrifugal governor is driven in dependence on the vehicle speed by shaft |90, as shown. As long as shaft does not rotate all the weights are in their lowest position, as repre. sented in Fig. l, wherein the fingers of all of the weights are out of touch with disc 3|. In this position, the piston 60 bears against the end plate 84. This corresponds to the initial position of the entire device when at rest or at slow speed of the centrifugal governor, i. e. at low speed of the vehicle, the control slide valve |60 being in the first speed position which will be described in a later passage.

When starting the engine, the weights come into the position in which the fingers of all of them bear against the disc 3|. The disc 3|', however, remains at first in the position shown in Fig. 1.

Assuming first, the operating lever 15 be in the position a, indicated in Fig. l which corresponds to the first operating step (engine speed, performance, and car speed step). As the operating lever 15 is connected to the fuel pump or carburetor 19 of the driving engine, this member is set at the same time. No pressure is exerted by means of members 15, 14, 66 on spring 65, so that this presses on the slide valve 64 with its lo,west pressure. As long as no oil was fed, the slide valve 64 was in its lowest position in which there is free access from the groove 10 ,through the ports 68 into the space 82 below the slide valve 6 As soon as the engine starts and the oil begins to flow, oil is supplied into the space 82 and by means of conduit 62 at the same time also into the space 83 of cylinder 6I. Consequently, slide valve 64 is pressed upwards until the oil pressure in space 82 keeps the balance to the force exerted by spring 65. If the oil pressure rises beyond the slide valve 64 is moved upwards higher than its middle position represented in the figure, permitting escape of oil through the ports 68 and the outlet orifices 69. Owing to the thus caused reduction in pressure in space 82, the slide valve 64 is immediately led back into its middle position. If the oil pressure drops below the value determined by the spring compression, the slide valve 64 is slightly pressed downwards, permitting thus admission of oil from conduit 12 into space 82 through the annular groove 10 and the ports 60. Consequently, the pressure in the space 82 below slide valve 64 increases and causes it to move back into its middle position. According to the pressure set by the control slide valve 64, the piston 60, too, is always loaded by the pressure oil embodied in the space 83.

Not before a certain number of revolutions is reached the centrifugal force of the weights II to I8 is sufficient to overcome the oil pressure existing in the space 83. With this number of revolutions i. e. with an adequate speed of the vehicle, all weights deflect. Thereby the disc 3| and the toothed bar |68 are moved upwards and the pinion |61 together with thefslide valve |60 are rotated to such extent that the latter moves from the first speed position into the second speed position. The control sections effective in these two speeds are indicated in detail in another passage oi this specification.

By the upward displacement of the rods 32 and 35 the piston 60 is also displaced within cylinder 6| in the upward direction, which causes the slide valve 64 to be lifted also a little so asto permit of the outflow of oil through the ports 68 and the outlet orifices 60 to such an amount that in the new position there exists again equilibrium between the centrifugal force of the weights and the oil pressure in the spaces 82 and 83. In this position the stops 2|, 22, 23, 24 of the four weights II I2, I3, I4 will have come to bear against the face 20 of the support 2. With the number of revolutions now prevailing any further movement of the disc 3| and the parts in connection with it by the remaining four weights |5|8 still capable of defiecting is impossible because the centrifugal force of the four weights |5-I8 is not sufficient to overcome the reaction of the oil pressure.

Supposing the velocity of the vehicle be further increased: At a certain number of revolutions of shaft I the centrifugal force of the four weights I5, I6, I1, I8 is so great that upward movement of disc 3| causes further rotation of the rotary slide valve |60 into the next position (third speed) and also upward movement of piston 60. The resistance acting against the force transmitted by the four centrifugal weights to the disc 3| is again the oil pressure existing in the spaces 83 and 82 which corresponds to the force transmitted by the spring 65 to the slide valve 64. The resistance acting against these four centrifugal weights is thus the same as the resistance acting before against all 8 centrifugal weights. But, not taking into consideration the friction of the slide valve |60 and assuming the same dimensions for all weights, the number of revolutions has risen to the double of the num-ber of revolutions with which the eight weights began to move. In the position now occupied by the weights II, I2, I3, I4 the weights I5, I6 with their extensions, too, Abear against the face 20.

If the number of revolutions increases iurther to about the double amount of n, the two centrifugal weights I1, I8 finally begin again to move and come also to stop at the face 20 with their extensions 21 and 28. Now, all eight weights are in their end positions. Thereby the slide valve has -been rotated so far that the fourth speed is engaged.

It the control is to be eiiected in another operating step, the operating lever 15 is taken from the position represented in Figure l which corresponds to step a into one of the other operating steps (b, c or d). Thereby spring 65 is put under higher tension by means of the rods 15, 14, 66 and, consequently, slide valve 64 is moved a little more downward causing connection -by means of the ports 68 between the circular groove 10 and the space 82, so that a higher oil pressure is created therein. Slide valve 64 will immediately return to its middle position, as explained above. Due to the increased oil pressure now existing in the spaces 82, 83 a greater force is set against the centrifugal weights. Therefore, a higher centrifugal force of the governor weights is wanted for causing their deflection and the change to the next position (gear change) which means that a higher speed of rotation of shaft I and consequently a higher car velocity is necessary therefor. The change-over from one of the afore-mentioned operating steps to the next one by means of the rotary slide valve |60 is thus effected at a number of revolutions corresponding to the higher oil pressure.

Whereas in the case exemplified the changeover during operation in an upper operating step takes place at a higher number of revolutions than in a lower operating step, the arrangement may as well be made to operate in the reverse l sense, so that when engaging an upper operating step. the change-over will take place at a lower number of revolutions than in a lower operating step. This has to be decided in accordance with the prevailing acquirements of operation.

Of course, the change up or down to another operating step is possible at any moment, irrespective of the position of the control device.

In Fig. 1 the change speed gearing is represented in the second speed. The numbers I, II, III, IV indicated in the cylinders |33 and |34 mark the positions of the pistons I3I and |32, respectively, in the corresponding speeds.

In the first speed, as may be seen from the table, the conduits |35 and |38 are connected to the pressure oil feeding conduit. Port 201 receives pressure oil from the bore |64 and delivers it into the conduit |35, whereas the port 20| supplies it into the conduit |36. Ports 203 and 205 and by them the conduits |31 and |36 are connected with the outlet bore |65. Consequently, piston |32 is in its right hand end position and piston |3I in its left hand end position; the change clutches I|1, II8 and II3, ||4 are engaged.

With the pistons |32, |3| in these positions the control valve I 45 is in its left hand position and the control valve |46 in its right hand position. Conduit is thus connected to the pressure oil feeding line |49 through the recess |41 while conduit |52 is connected with the outlet port |54 through recess |48. From the interior of the cylinder |12 the pressure oil is allowed to escape by the orifice |82 and the recess |13. The spring |69 forces the control slide valve |60 to the right and holds the piston |15 against the right hand inner cylinder bottom of cylinder |12 (by means of members |16, |11). But cylinder |12 remains in its left hand position inside of cylinder |1|, because pressure oil is admitted by conduit |5|. Consequently, the control slide valve |60 is in its middle position when the first speed is engaged, i. e. the orifice 252 which is in connection with the bore |64 supplying pressure oil coincides with the opening of conduit |55 and supplies through it pressure oil to the engaging and disengaging device of the friction L clutch |02 so that the latter is engaged.

The travelling paths of the control slide valve |60 relative to the mouths of the conduits |35- |38 and |55 when speeding up from first into second, third and fourth speed, are indicated in Fig. 3 in dash-dotted lines. The travelling paths of the control slide valve |60 when slowing down from the fourth into the third, second and first speeds are also indicated, but in dashed lines.

If now, by a device as represented in Figs. 1 and 2, the control slide valve |60 is rotated by the toothed bar |68 and the gear |61, whereby the rows of ports in the control slide valve |60 come to coincide one after the other with the openings of conduits |35, |36, |31, |38 and |55 in the casing |6| in accordance with the stepwise movement of the toothed bar |68. When changing to the second speed, after rotation of the slide valve |60 from position I into position II, the port 2|| is connected with |38, 2|3 with |31, 2|5 with |36, 2|1 with |35 and 262 with |55. Pressure conditions in the conduits |38 and |31 remain the same as in the first speed so that there is no change in the respective situation of the clutch halves ||5, ||6 and ||1, ||8. The clutch ||1, ||8 remains engaged. In the conduits |35 and |36 the pressure conditions are reversed as compared to the first speed. Since conduit |55 is connected to the outlet through the orifice 262 and the channel |65, the oil pressure in the engaging device of the friction clutch |02 is released, the latter is disengaged, Pressure oil flows from the port 2|5 through the conduit |36 and arrives on the left hand side of the piston 3| while conduit |35 is released by the port 2|1, The piston |3| is thus moved to the right. The clutch halves ||3 and ||4 are disengaged, and clutch halve is shifted to come in touch with clutch half ||2. In the case exemplified overrunning clutches of a wellknown type with inclined front faces of the claws are provided which, at first, will repulse each other. After the overrunning speed has been attained, the clutch ||2 engages. During the second half of the stroke of piston |3| to the right the control valve is also displaced to the right so that conduit |5| is released by the recess |41 and the port |53. The pressure oil can now escape on the right hand of cylinder |12 from cylinder |1|, and cylinder |12 together with the control slide valve |60 is moved into the right hand end position by means of spring |69. In this right end position pressure oil is supplied to the conduits |38 and |36 through the ports 2|| and 2|5 whereas the port 26| has arrived in front of conduit |55 so that the latter is again fed with pressure oil, the main clutch |02 being engaged thereby. The second speed is set. This position is represented in Fig. 1.

When changing over from the second into the third speed after rotation of the slide valve |60 from position 1I into position III, pressure oil is supplied to conduit |31 through the port 223, while conduit |38 is released through port 22|. Pressure conditions in conduits |36 and |35 at first remain the same because the pressure oil supply into conduit |36 through port 225 continues and conduit |35 remains released by the port 221. The conduit |55 is connected to the outlet by the orifice 21|. 'I'his means disengagement of the friction clutch |02. The piston |32 is moved to the left, the clutch halves 1, ||8 are disengaged and the clutch halves ||5, ||6 are engaged. At the same time the control valve |46 is moved to the left and pressure oil is supplied into the interior of the cylinder |12 from conduit |50 through the recess |48, the conduit |52, through the recess |13 and by the orifice |82, so that the piston |15 and consequently the control slide valve |60 are moved from their right hand end positions which they had in the second speed to the left into the middle position of member |60.

By the movement of the control slide valve |60 to the left the port 212 comes to coincide with the mouth of conduit |55, the latter remaining still connected to the outlet. Thus. the friction clutch |02 remains disengaged. Furthermore, the port 221 arrives in front of the mouth of conduit |35, land port 226 in front of the mouth of conduit |36. Pressure conditions in the conduits |36 and |35 are reversed and the piston |3| is shifted to the left, the clutch halves ||3. ||4 being engaged and the clutch halves ||2 disengaged, At the same time the control valve |45 is moved to the left so that pressure oil is supplied into the cylinder l1| from the conduit |49 through the recess |41 and the conduit |5|. The cynnder |12 with piston |15 is shifted to the left against the tension of the spring |69, the control slide valve |60 being moved into its left hand end position. In this position of the slide valve |60 pressure oil flows again into the conduit |55 through the port 213. 'I'he clutch is engaged. The change-over into the third speed is established.

As compared with the other ports, the ports 262, 21| and 283 are a little enlarged in the direction of rotation of the slide valve |60 when speeding up, and the ports 25|, 263, 212 in the direction of rotation of the slide valve when slowing down, in order to release the clutch |02 always a short time before the gear change is performed.

When changing over into the fourth speed the conduit |55 is released by the port 283 after rotation of the slide valve |60 from the position III into the position IV. The clutch |02 is disengaged. Pressure condltions in the conduits |31 and |38 remain the same as in the third speed, but in the conduits |35 and |36 they are reversed. The piston |3| is moved to the right. The clutch halves ||3, ||4 are disengaged and the clutch halves and ||2 are engaged. The control valve |45 moves to the right so that the conduit |5| is released through the recess |41 and the port |53. The cylinder |12 with the plston |15 moves to the right under the action of spring |69, the piston 15, however, in the cylinder |12 remaining in its left hand end position owing to the pressure of the oil supplied by the conduitl |52, through the recess |13 and the port |82. The control slide valve is again in its middle position, pressure oil is supplied into the conduit |55 by the port 282 and the clutch is again engaged. The fourth speed is put in.

The slowing down from the fourth speed into the third, second and first speeds is performed in a similar manner as the speeding up described in the preceding passages. In the various speeds, the control slide valve |60 travels the path indicated by a dashed line in Fig. 3 in relation to the mouth of conduit |55.

Fig. 4 represents a further modification of the main control member. In this example it is a cam shaft 360 capable of being shifted and rotated in the casing 36| The elements designated by the numerals 366, 369, 316, 311 correspond to the elements |66, |69 and |16, |11 of Fig. 1, respectively, and the conduits 362, 338, 331, 336, 335 and 355 correspond to the conduits |62, |38, |31, |36, |35, |55 of Fig. 1, respectively.

Into the conduit 362 running alongside the casing 36| and serving for the supply of pressure means the valves 400, 4|0, 420, 430, 440 are inserted as control elements for the supply of auxiliary force to the shifting members of the change speed gear and of the main clutch. These valves each have two closing bodies 40|, 402; 4||, 4|2; 42|, 422; 43|, 432; 44|, 442. The lower ends of the valves are provided with projections 403, 4 |3, 423, 433, 443. There are springs 404, 4|4, 424, 434, 444 pressing the valves with their projections against the circumferential surface of the cam rod 360. 405, 4|5, 425, 435, 445 are air discharging ports. The cam rod 360 has for each control position a peculiar longitudinal proflle and peculiar sections. It is rotated by the governor and displaced by the pistons |12 and |15 of Fig. 1 and thus brought into adequate positions for the various speeds, in the same manner as the main control slide valve |60 in Fig. l.

In Fig. 4 the position of the cam shaft for the first speed is represented. The valves 400 and 430 are in their lower positions so that the conduits 338 and 355 receive pressure oil by the conduit 362. The valves 4|0, 420 and 440 are in their upper end positions so that the conduits 331, 336, 355, respectively, are released by means of ports 4|5, 425, 445, respectively. In the other speeds equal pressure conditions are prevailing in the various conduits as in the corresponding conduits of Figs. 1 and 3.

We do not want to be limited to the details described or shown in the drawings, as many variations will occur to those skilled in the art without deviating from the scope of our invention.

What we claim is:

1. In a power transmission device for motor vehicles, in combination: an internal combustion engine having a throttle, a driving shaft driven by said engine, a change speed gear, a driven shaft, a fluid pressure operated device for causing speed changes, a source of fluid under pressure connected with said device for causing speed changes, manually operated means for controlling said fluid pressure operated device in accordance with the positions of said throttle, said fluid pressure operated device comprising a main operating member, means for controlling said member operating in dependency on the vehicle speed, further control means for said same member operating in dependency on the position of certain elements performing the speed changes.

2. The structure defined in claim 1 wherein the change speed gear comprises a pair of 'clutches adapted to be shifted into and out of engagement alternately by said power operated device.

3. The structure defined in claim l wherein said main operating member comprises a substantially cylindrical control element adapted to be rotated stepwise and also to be shifted longitudinally.

4. The structure defined in claim l wherein said main operating member comprises a fluid pressure control element adapted to be rotated and also to be moved longitudinally, said eiement being provided with longitudinal bores, one for admitting fluid pressure and one for venting fluid pressure.

5. The structure defined in claim 1 wherein said manually operated means comprises a spring operated by a lever, and fluid pressure means connecting said spring to said main operating member, said fluid pressure means comprising a piston adapted to be moved in a cylinder in one direction by said spring and in the opposite direction by fluid pressure.

6. In a motor vehicle, an internal combustion engine, a change speed gear transmission driven by the engine, a shaft driven by the transmission, shift motor means selectively operative to shift said transmission, control means for the motor means, and actuating means for the control means comprising a fluid pressure chamber, adjustable means for controlling the fluid pressure in said chamber, said adjustable means also controlling the engine speed, means responsive to fluid pressure in said chamber to move the control means in one direction, and means responsive to the speed of the driven shaft to move the control means in the opposite direction only.

'1. The structure defined in claim 1 further including fluid control valves, said operating member comprising a fluid pressure control element adapted to be rotated and to be moved longitudinally. said control element forming a cam shaft adapted to actuate said fluid control valves, said fluid pressure controlled by said main operating member controlling said change speed gear.

RICHARD LANG. FRI'IZ KOCH. 

